AudioWaveformCreator.java

		public void createWaveForm(byte[] audioBytes) {
			lines.removeAllElements();  // clear the old vector

			AudioFormat format = audioInputStream.getFormat();
			if (audioBytes == null) {
				try {
					audioBytes = new byte[
							(int) (audioInputStream.getFrameLength()
									* format.getFrameSize())];
					audioInputStream.read(audioBytes);
				} catch (IOException ex) {
					ex.printStackTrace();
					return;
				}
			}

			int[] audioData = null;
			if (format.getSampleSizeInBits() == 16) {
				int nlengthInSamples = audioBytes.length / 2;
				audioData = new int[nlengthInSamples];
				for (int i = 0; i < nlengthInSamples; i++) {
					if (format.isBigEndian()) {
						/* First byte is MSB (high order) */
						int MSB = audioBytes[2 * i];
						/* Second byte is LSB (low order) */
						int LSB = audioBytes[2 * i + 1];
						audioData[i] = MSB << 8 | (255 & LSB);
					} else {
						/* First byte is LSB (low order) */
						int LSB = audioBytes[2 * i];
						/* Second byte is MSB (high order) */
						int MSB = audioBytes[2 * i + 1];
						audioData[i] = MSB << 8 | (255 & LSB);
					}
				}
			} else if (format.getSampleSizeInBits() == 8) {
				int nlengthInSamples = audioBytes.length;
				audioData = new int[nlengthInSamples];
				if (format.getEncoding().toString().startsWith("PCM_SIGN")) {
					for (int i = 0; i < audioBytes.length; i++) {
						audioData[i] = audioBytes[i];
					}
				} else {
					for (int i = 0; i < audioBytes.length; i++) {
						audioData[i] = audioBytes[i] - 128;
					}
				}
			}

			if (audioData == null) return;

			int width = 1000;
			int height = 200;

			final int bucketCount = width;
			final int bucketSize = audioData.length / format.getChannels() / bucketCount;
			final double[] buckets = new double[bucketCount];
			for (int bucketIndex = 0, sampleIndex = 0; bucketIndex < bucketCount; bucketIndex++) {
				double sum = 0;
				for (int b = 0; b < bucketSize; b++) {
					for (int c = 0; c < format.getChannels(); c++) {
						sum += Math.abs(audioData[sampleIndex++]);
					}
				}
				buckets[bucketIndex] = sum / bucketSize;
			}

			for (int i = 0; i < buckets.length; i++) {
				double d = buckets[i];
				lines.add(new Point2D(i,d));
			}

			saveToFile(width);
		}

		public void saveToFile(int w) {
			int h = 200;

			BufferedImage bufferedImage = new BufferedImage(w, h, BufferedImage.TYPE_INT_ARGB);
			Graphics2D g2 = bufferedImage.createGraphics();

			createSampleOnGraphicsContext(w, h, g2);
			g2.dispose();

			try {
				ImageIO.write(bufferedImage, "png", outputImg);
			} catch (IOException e) {
				e.printStackTrace();
			}
		}


		private void createSampleOnGraphicsContext(int w, int h, Graphics2D g2) {
			g2.setComposite(AlphaComposite.Clear);
			g2.fillRect(0, 0, w, h);

			g2.setComposite(AlphaComposite.Src);
			if (audioInputStream != null) {
				g2.setColor(Color.WHITE);
				for (Point2D line : lines) {
					g2.drawLine((int) line.getX(), 100, (int) line.getX(), 100 + (int) line.getY());
				}
			}
		}
	}